PHOSU

Phosphate, Random Urine

Urine, Clean container 

Urine, minimum volume 10 mL

Clean container

Specimen Type	Temperature	Time
Random urine	Refrigerated, 2oC to 8oC	7 days at pH <5
Random urine	Frozen, -20oC	30 days at pH <5

PHOSU

Phosphate, Random Urine

Phosphomolybdate

Tested daily (24 hours)

Collected specimen to report within 1.5 hours (90 mins)

Chemistry, Laboratory Department Tel. 13224

7 days

PHOSU

Phosphate, Random Urine

Approximately 80% of filtered phosphorus is reabsorbed by renal proximal tubule cells. The regulation of urinary phosphorus excretion is principally dependent on regulation of proximal tubule phosphorus reabsorption. A variety of factors influence renal tubular phosphate reabsorption, and consequent urine excretion. Factors which increase urinary phosphorus excretion include high phosphorus diet, parathyroid hormone, extracellular volume expansion, low dietary potassium intake and proximal tubule defects (eg, Fanconi Syndrome, X-linked hypophosphatemic Rickets, tumor-induced osteomalacia). Factors which decrease, or are associated with decreases in, urinary phosphorus excretion include low dietary phosphorus intake, insulin, high dietary potassium intake, and decreased intestinal absorption of phosphorus (eg, phosphate-binding antacids, vitamin D deficiency, malabsorption states).

A renal leak of phosphate has also been implicated as contributing to kidney stone formation in some patients.

Interpretation of urinary phosphorus excretion is dependent upon the clinical situation, and should be interpreted in conjunction with the serum phosphorus concentration.

1. Manufacturer’s reagent package insert, Architect® Phosphorus, Abbott Laboratories, Abbott Park IL 60064 USA, January 2016.
2. http://www.mayomedicallaboratories.com (Retrieved: 01 Jan 2019)